CHARLOTTE, N.C. — All in all, Monday proved to be a painful night for the Boston Celtics.

Not only did the Celtics have their seven-game losing streak snapped at the hands of the NBA’s worst team, but they might have suffered yet another costly injury in their 94-91 loss to the Charlotte Bobcats.

Backup guard Leandro Barbosa, who has seen increased playing time since the season-ending injury to Rajon Rondo, injured his left knee late in the third quarter and had to be carried to the locker room by a trainer and teammate.

Coach Doc Rivers said Barbosa will have an MRI on Tuesday.

“It doesn’t look great but we’ll see,” Rivers said.

In the seven games since Rondo’s injury Barbosa had averaged nine points while playing an average of 22.5 minutes. The Celtics had won all seven games.

All of that came crashing down Monday night.

This night belonged to Charlotte’s unheralded big man, Byron Mullens.

The four-year NBA veteran turned in a career game with 25 points and 18 rebounds as the Bobcats snapped a seven-game losing streak.

The 7-foot Mullens hit 10 of 16 shots from the field, including 4 of 5 from 3-point range. Ramon Sessions had 19 points for the Bobcats, including the go-ahead jumper from 18 feet with 25.7 seconds left. Kemba Walker had 18 points, six assists and six rebounds, and Gerald Henderson chipped in with 16 points.

Mullens was playing his fifth game after missing 19 with an ankle injury.

“It’s big time,” Walker said of Mullens’ effort. “We need that from him. We need that from Byron and he can do it. We know he can do it every night. He is very capable. When he has big games like that, you know, I think that gives us a much better chance.”

Mullens said he was more pleased with his rebounding than his scoring “because that is not what I’m known for.

“I just have to show the league and this organization that I can rebound,” he said.

Kevin Garnett had 16 points and 13 rebounds for the Celtics, but missed a key 18-footer that would have given Boston the lead late in the game. Paul Pierce and Avery Bradley had chances to send the game into overtime in the final seconds, but missed open 3-pointers.

Jeff Green had 18 points for the Celtics and Pierce finished with 13 points, eight assists and eight rebounds.

“We had a win streak going and we had momentum going,” Celtics guard Courtney Lee said. “We wanted finish out the rest of these games going into the (All-Star) break. So it’s definitely a letdown. This one hurts more because we had the lead with one minute to go.”

It was a back-and-forth game throughout.

After Henderson gave the Bobcats an 85-84 lead with 3:58 remaining, Jason Terry made a 3 from the wing and Garnett followed with a turnaround jumper in the lane to push the Boston lead to four.

It appeared as though the Bobcats were on their way to another fourth quarter collapse.

But trailing by four, Henderson hit a 3-point with 1:01 left. After Bradley missed an open jumper, Sessions came free off a screen and knocked down an 18-footer to give the Bobcats the lead with 25.7 seconds remaining.

The Celtics called timeout but Garnett missed from the left wing. Mullens grabbed his 18th rebound and the Walker made a pair of key free throws to give the Bobcats a three-point lead with 14.8 seconds left.

Boston set up an inbounds play and Pierce got an open look but missed. He grabbed his own rebound and dished out to the wing for Bradley, but he missed a 3 as time expired.

Boston’s loss came after a triple overtime win against Denver on Thursday night, but the Celtics refused to use fatigue as an excuse.

“We put that one behind us,” Green said.

As he’d planned to do before the game, Rivers went deep into his bench in the first half with 10 players seeing at least 10 minutes of action.

The Bobcats battled back in the third quarter behind 12 points from Mullens to take a 75-72 lead into the fourth. Mullens, who scored Charlotte’s first 10 points of the game, did most of his damage from outside, knocking down 3-pointers and turnaround jumpers, showing great touch for a big man.

Hawks 105, Mavericks 101

DALLAS — Josh Smith had 26 points and 13 rebounds, Devin Harris made a key steal in the final minute and the Atlanta Hawks beat the Dallas Mavericks 105-101 Monday night.

Al Horford had 21 points and 10 rebounds and Jeff Teague scored 20 points to help the Hawks win for just the second time in their last 10 road games.

With the Hawks up 99-98, Harris poked the ball from a driving O.J. Mayo and saved the ball from going out of bounds with 23.9 seconds left.

Dirk Nowitzki scored 24 points and Mayo added 19 for the Mavericks, who have lost two of the first three on a five-game homestand.

Dallas, which didn’t lead until the fourth quarter, pulled ahead 91-86 on five straight points from reserve Brandan Wright. Smith responded with a dunk and 3-pointer to tie the score midway through the fourth.

Smith whipped a pass to Horford for a dunk that stretched Atlanta’s lead to 96-92 and he hit a 3-pointer over Nowitzki that made it 99-94 with 1:29 left.

Nowitzki connected on a pair of free throws and short shot over Smith that cut it to 99-98 with 44.9 seconds remaining.

Smith lost the ball to Elton Brand and Mavericks got the ball in transition to Mayo, who was driving for the go-ahead basket. Harris, who was drafted by Dallas in 2004, sneaked up from behind and tipped the ball from Mayo. He saved the ball to Smith and the Hawks hit all six of their free throws in the final 22.2 seconds to preserve the victory.

Harris scored 15 points for Atlanta, which has gone 8-12 since starting the season 20-10.

Darren Collison scored 14 points and Vince Carter chipped in with 13 for the Mavericks.

The Hawks led by 13 in the first half before the Mavericks rallied to pull to 49-48 at halftime.

Collison’s 3-point play tied the score at 64 midway through the third.

Kyle Korver hit a 3-pointer in transition and John Jenkins followed with a basket to give Atlanta an 82-74 advantage.

The Mavericks scored seven points over the final 1:04 of the third, capped by two free throws from Nowitzki, to pull to 82-81.

NOTES: Atlanta coach Larry Drew said Smith hasn’t paid much attention to hearing his name in trade rumors as the Feb. 21 deadline approaches. “He’s been able to keep his focus and be professional about it,” Drew said. ... The Mavericks have scored 100 points in 13 of their last 15 games. ... Korver has hit a 3-pointer in 44 straight games, the longest active streak in the NBA.